Man has employed many types of fences having different characteristics to indicate property lines, ensure privacy, segregate activities, and provide barriers for property, people and animals. For example, fences made of stones, bricks, and concrete have long service life, but are difficult to alter after construction. Wood fences have low initial cost, are flexible to alter, but have shorter life when exposed to severe climate or pest infestation. Metal fences having insertable panels are durable, pest resistant and have good service life, but have other problems. For example, the manufacturing tolerances necessary to assemble the metal fences make them vulnerable to vibration and noise generation in wind. One metal fence has lateral stiffeners to hold corrugated sheet metal panels, but the stiffener is a fixed width which limits its application to one width of corrugated sheet metal panel. Another metal fence uses a molded polyvinyl chloride (PVC) interlocking sleeve to hold the fence panels. The interlock sleeve is a fixed width, however, which again restricts flexibility in panels that can be used. In addition, sun exposure degrades the molded PVC interlocking sleeve over time destroying the integrity of the fence.
Fences also fail to address certain problems. For example property boundaries are often polygons, that is, closed figures made up of line segments. Two adjacent line segments often form a non-perpendicular angle. Thus, fence sections join at non-perpendicular angles yet need freedom to adjust the angle during construction while maintaining connection strength. Separately, gate widths are often oversized to make sure the gate fits, then a lip or shim added to the gate to cover the gap. This lip/shim technique is labor intensive and affects the appearance of the gate. Another problem concerns the attachment of the gate to the fence post. Gates are cantilever structures which stress the gate hinges. The wider or heavier the gate, the more load the hinge must support. The load can fatigue or deform the hinge causing the gate to sag, the hinge hardware to loosen, and even cause damage to the gate frame or gate post. In some cases, if this damages the gate frame or gate post too much, the gate hinges will need to be relocated.